tion of the C-ring of the quasi-dimeric alkaloid decreases the activity. Harman, dihydroharman, and a synthetic bisharman (34) were found to be inactive in this test system at the concentrations tested.
SYNOPSISFourier transform infrared spectroscopy was used to investigate, without any destructive interference, interactions of the cryoprotective agents, glycerol and dimethyl sulfoxide with Brudyrhizobium juponicum. The intracellular spectrum of glycerol, obtained by subtracting the spectrum of control bacteria from that of glycerol-treated bacteria, showed no differences in infrared features compared to that of pure glycerol. This was not the case when dimethyl sulfoxide treatment was used. The intracellular spectrum displayed important modifications compared to that of the pure chemical. Spectral analysis showed that glycerol and dimethyl sulfoxide uptake required only a few minutes. Moreover, the infrared features resulting from the presence of pure glycerol, in bacteria, were still existent for up to 2 or 3 hours after thawing process. The deconvoluted Amide I and Amide I1 bands of bacterial proteins reflected important changes in secondary structure after treatment of bacteria with dimethyl sulfoxide (increase in &sheet and loss of random coil content). In contrast to glycerol, the cryoprotective action of dimethyl sulfoxide probably involves interactions with a wide range of intrabacterial species.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.